Mason and Dixon began surveying the North-South or Tangent Line that marked the boundaries of Maryland and Pennsylvania, including the Three Lower Counties of Delaware, at the southwestern corner of present-day Delaware in June 1764. Moving northward, they reached this point on July 30, forty-five miles from where they started. They later returned to replace temporary markers with stones imported from England. Mile point stones bore the letters P and M, while five-mile points such as this one carried the coats of arms of the Calverts and Penns, proprietors of the colonies. In 1904, Maryland officials removed the stone for exhibition at the St. Louis World's Fair. It was later displayed in the State House in Annapolis and then placed in storage. After citizens of Marydel requested its return, the stone came back in 1954 and was moved a short distance from the roadside to its present location in 1968.